Re: [PATCH] ALSA: trident: Fix a memory leak in snd_trident_create

From: Takashi Iwai
Date: Sat Jul 11 2020 - 05:17:16 EST


On Sat, 11 Jul 2020 09:08:30 +0200,
Navid Emamdoost wrote:
>
> In the implementation of snd_trident_create(), the allocated trident is
> leaked if snd_trident_mixer() fails. Release via snd_trident_free().

No, this patch would result in double-free.

The manual release of trident object isn't needed once after it gets
added via snd_device_new(). Then it'll be automatically released at
the error path (via snd_trident_dev_free()).


thanks,

Takashi

>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
> ---
> sound/pci/trident/trident_main.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/sound/pci/trident/trident_main.c b/sound/pci/trident/trident_main.c
> index 6e50376163a2..e98c692f6aa9 100644
> --- a/sound/pci/trident/trident_main.c
> +++ b/sound/pci/trident/trident_main.c
> @@ -3582,8 +3582,11 @@ int snd_trident_create(struct snd_card *card,
> return err;
> }
>
> - if ((err = snd_trident_mixer(trident, pcm_spdif_device)) < 0)
> + err = snd_trident_mixer(trident, pcm_spdif_device);
> + if (err < 0) {
> + snd_trident_free(trident);
> return err;
> + }
>
> /* initialise synth voices */
> for (i = 0; i < 64; i++) {
> --
> 2.17.1
>